The tools on the Grid toolbar and the Grid menu can be used to display the grid, size it, and change its origin.
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Display
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Grid
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Hotkey: * Alt + G
Displays or hides the grid. This command is a toggle function.
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Double
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Grid
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Doubles the spacing of the grid, making it less dense.
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Halve
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Grid
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Divides the spacing of the grid in two, making it more dense.
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Set
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Grid
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Origin
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Select the new origin for the grid, or enter coordinates in the Coordinate Fields. You can use Set Origin to align the grid to a particular point, then use the grid to set future distances.